lot of people have been criticizing bitcoin in a negative way. I think they don't really know bitcoin after all or they just hate the fact that some people keep on investing in bitcoin even if its a risky decision and yet, no assurance to be profitable at the end of the day.
This is more of people's ignorance and are close minded people who refuse to know the truth. Once they set their mindset hating about bitcoin, i think they will really stand for it to the extent of slandering bitcoin. But in the end, what they did are still useless because bitcoin seems to grow even more despite of people's negative criticism.
Actually I prefer to say it's not a criticism, but an expression of disappointment over the losses that befell them due to falling price. Buying without analysis seem to be the main reason why they seem to be in a trance when the price drops and also they don't really understand that volatility is always present in crypto trading in general.
They should never go wrong with bitcoin when the price drops but they should blame themselves for not doing some analysis before buying anything in the market including bitcoin.